Justin Bieber responded to Donald Trump's reported assistance with A$AP Rocky's Swedish imprisonment, tweeting his gratitude for Trump's support while also addressing the crisis at the U.S. border, where migrant children are being detained and held in cages.

"I want my friend out.. I appreciate you trying to help him. But while [you're] at it
@realDonaldTrump can you also let those kids out of cages?" Bieber tweeted him.

Bieber also tweeted a Change.org petition asking for Rocky to be released from Swedish officials. The petition has over half a million signatures and is still growing.

Trump recently tweeted that he spoke with Kanye West and vowed that he would call the Prime Minister of Sweden to resolve the situation. Trump later added that he did in fact speak with Prime Minister Stefan Löfven, who "assured" him that Rocky will be treated fairly. Trump also vouched for Rocky's bail. The teams will be speaking again within 48 hours to try and resolve his imprisonment.

On July 3, Rocky was detained in Sweden following an altercation that saw him arrested. Rocky was in town for a festival performance and has been detained ever since his arrest. A judge ruled that Rocky will be in custody through July 25.

22 Things You Didn't Know About Justin Bieber